Chief Executive Leung Chun-ying brushed off the question of political neutrality yesterday as he publicly added his signature to the petition denouncing the Occupy Central movement.

"There is no neutrality in it," he said when asked if he should have refrained from taking sides. "There is no 'middle area' between breaking the law and not breaking the law."

Coming just hours after the Democratic Party met Beijing's top representative in the city, Zhang Xiaoming , Leung's signing raised questions about whether political divisions would be deepened at a time when a middle ground is being sought on reform.

Petition co-organiser and Alliance for Peace and Democracy leader Robert Chow Yung defended the chief executive's action, saying Leung's signing was "high profile" only because journalists "chose to cover" it.

But Leung's plan was publicised yesterday afternoon when the government's Information Services Department announced he would sign the petition and meet the media at the General Chamber of Commerce's Admiralty office at 5.15pm. He was accompanied by his office director Edward Yau Tang-wah, Chow and two alliance spokesmen.

Leung dismissed suggestions he was misusing public resources by signing the petition during working hours and bringing his media relations team.

The chief executive said he was signing the petition in a "personal capacity" and brought his team because he knew reporters would be interested about matters other than the petition.

Leung joins at least five high-level officials who have signed the alliance's petition - among them health chief Dr Ko Wing-man, Education Secretary Eddie Ng Hak-kim and development chief Paul Chan Mo-po.

Chinese University political scientist Ma Ngok said Leung's participation in the anti-Occupy campaign was tantamount to showing that "the government is declaring war on Occupy Central". This would encourage civil servants and policemen to voice their opposition to the civil disobedience movement, he said.

Leung's signing of the petition came as police finalised plans for handling a series of protest rallies to be held tomorrow by Chow's alliance to oppose planned civil disobedience protests and show support for the government.

The force declined to address questions about the size of the demonstration, citing confidential operation planning.

"We will have a suitable deployment and flexible manpower planning ... and we will carry out our duty in a fair and impartial manner," Senior Superintendent Tan Wing-yuen said.

Alliance organisers say they expect about 120,000 people to march from Victoria Park in Causeway Bay to Chater Garden in Central.

Thousands of government supporters are also expected to run along the rally route early on Sunday.

The petition calls for universal suffrage in time for the chief executive election in 2017 - a goal it shares with Occupy Central - but it specifies that must happen in a "peaceful and non-violent manner" without occupying Central and bringing it to a standstill.